Fluid pressure and dynamic brake interlock apparatus



April 20, 1954 FLUID PRESSURE Filed July 28, 1950 A. T. GORMAN ETAL 2,676,064

AND DYNAMIC BRAKE INTERLOCK APPARATUS 5 Sheets-Sheet l INVENTORS Andrew 1? German Earle 61 000K A TTORNE Y April 20, 1954 A. T. GORMAN ET-AL ,676,064

FLUID PRESSURE AND DYNAMIC BRAKE. INTERLOCK' APPARATUS Filed July 28, 1950 3 Sheets-Sheet 2 Dqnomic Brake Power on 82 85 86 126 84 i4 21 19 INVENTORS' Ancfi'eu) 7? Gomzan Earle 8. 000K A T TORNE Y April 1954 A. T. GORMAN ETAL 2,676,064

FLUID PRESSURE AND DYNAMIC BRAKE INTERLOCK APPARATUS Filed July 28, .1950 :5 Sheets-Sheet s I 'IIIIA INVENTORS' Andrew T. German Earle S. (3 00K A TTORNE. Y

Patented Apr. 20,1954

FLUID PRESSURE AND DYNAMIC BRAKE INTERLOCK APPARATUS Andrew T. Gorman, Pitcairn, and Earle S. Cook, Forest Hills, Pa., assignors to Westinghouse Air Brake Company, a corporation of Pennsylvania Application July 28, 1950, Serial No. 176,404

This invention relates to brake apparatus and more particularly to brake apparatus for the use on electrically propelled locomotives.

Certain multiple unit locomotives such as the diesel electric type are equipped with Westinghouse Air Brake Companys No. 8EL locomotive brake equipment for braking the locomotive pneumatically and electric propulsion motors on the locomotive are adapted to operate as generators for supplying electric current to dynamic braking resistors for providing electric braking.

The No. 8EL locomotive brake equipment comprises a distributing valve device and an engineers brake valve device consisting of an automatic portion and an independent portion. The automatic portion is provided for reducing the pressure of fluid in the usual brake pipe to cause operation of the distributing valve device on the locomotive and of triple valves or the like on cars of a train to effect an automatic application of the fluid pressure brakes thereon, while the independent portion is provided for controlling the fluid pressure brakes on the locomotive independently of those on the cars of the train. If

both the fluid pressure brakes and electric brakes on the locomotive are efiective at the same time undesired slipping and wear of the locomotive wheels may occurso that while it is normally undesirable that both of the brakes be efiective on the locomotive at the same time it is however desirable under certain conditions to be able to apply the fluid pressure brakes on the locomotive while the electric brakes are eiiective.

The principal object of the invention is therefore the provision of an improved locomotive brake equipment embodying both fluid pressure and electric braking means and interlock means so arranged as to prevent an automatic application of the fluid pressure brakes on the locomotive at the same time as when the electric brakes are efiective, but which permits application and release of the fluid pressure brakes on the comotive by operation of the independent portion of the brake valve device when the electric brakes are effective.

Other objects and advantages will become apparent from the following more detailed description of the invention.

In the accompanying drawings, Figs. 1, 1a, when the right-hand edge of Fig. 1 is matched to the left-hand edge of Fig. la, is a diagrammatic view, mainly in sectiom'of a portion of a locomotive brake equipmentembodying the invention; Figs. 2 and 3 are sectional views of an independent brake valve device shown in Fig. l but with 21 Glaims. (Cl. 303--3) of the invention.

the rotary valve thereof in difierent positions; Fig. 4 is a diagrammatic view of a portion of an engineers automatic brake valve device shown in Fig. 1 but with the rotary valve thereof in a difierent position; Fig. 5 is a diagrammatic View of the equalizing portion'of a distributing valve device shown in Fig. la but with the parts thereof shown in a different position; and Figs. 6, '7 and 8 are diagrammatic views of modifications Description As shown in the drawing, the pneumatic brake equipment for each unit oi"v a multiple unit locomotive comprises a distributing valve device I, a brake cylinder device 2 and a main reservoir 3. On the lead locomotive unit there is also provided an engineers brake valve device comprising an provided an engineers controller 8 having a power-on position and a dynamic-brake-on position as indicated by suitable legends. In the pgweron position. a contact 9 in the controller will bridge a pair of contacts l0 and H .for completing a circuit for supplyingcurrent to the motor 6, said circuit being by way of example from a current supply wire 12, the. contact 9, a wire [3,

motor 6 and a grounded conductor l4. In the dynamic-brake-on position a contact [5 is adapted to bridge contacts H and NS for placing motor 6 in adynamic braking circuit includingresister 1 which 'is efiective to produce dynamic braking upon. operation of the motor 6, as a gen-g erator, in a well-known manner.

According to the invention, we add to the brake apparatus above described an interlock de.-

vice I! one of which will be employed on each 10.- comotive unit. For each unit-we also add a dy namic brake cut-out switch device l8.

In the drawing, only the brake equipment for the leading unit of a locomotive is shown as it is deemed sufiicient for'a clear understanding of the invention, but it is desired to" point out that a distributing valve device l,'interlock device I1 and switch device I8 will be provided on' all other units of the locomotive, the like devices on all units being adapted to operate in synchronism with and in thesam'e manner as those on the leading unit of the locomotive, as will be subsequently described.

The numeral I9 designates a brake pipe adapted to extend through the locomotive for connection with the brake pipe on a train, said pipe being connected to the distributing valve device I, to the interlock device IT and to the engineers automatic brake valve device 4. The numeral designates a main reservoir pipe adapted to ex-; tend through the locomotive and on each unit to be connected to a mainreservoir 3, to the distributing valve device I, to the interlock device IT and also to the engineers brake valve device on the leading unit of the locomotive. Numeral 2i designates the usual controlled emergency pipe connected to the independent brake valve device 5 and to the distributing valve device I at least on the leading unit of the locomotive while in some cases said pipe may extend completely through the locomotive for connection with each distributing valve device thereon. Numeral 22 designates the usual independent release pipe adapted to extend through the locomotive for connecting thedistributing valve device I on each unit to the independent brake valve device on the leading unit. Numeral 23 designates the usual independent application pipe also adapted to extend through the locomotive for connection with each distributing valve device and to the independent brake valve device 5, the connection between said pipe and the distributing valve device, according to the invention, being interlocked through the interlock device IT, as will be later described.

The distributing valve device 1, and the engineers automatic brake valve device 5 and independent brake valve device 5' are substantially the same as fully disclosed in Westinghouse Air Brake Companys No. 8EL Locomotive Brake Equipment Pamphlet No. 50324, Sup. 3, dated November 1943 and also substantially the same as the locomotive brake equipment fully disclosed in Patent No. 2,009,841 issued to Ellis E. Hewitt on July 30, 1935. The structure and operation of such brake equipment is well-known and only such portions thereof have been disclosed in the drawing and will hereinafter be described as deemed essential to an understanding of the invention.

As shown in the drawing the distributing valve device I comprises an application portion 21, an equalizing portion 28, a reduction chamber cutoff valve device 29, a release valve device and a safety valve device 3| all of which parts are carried by a pipe bracket 32 in which there is provided a reduction chamber 33. Also carried by the pipe bracket 32 is a controlled emergency or delay valve device 34. The pipe bracket 32 is in turn carried by a reservoir. portion in which there are, provided a pressure chamber 85 and an application chamber 35. H

The application portion 21 of the distributing valve device comprises a fluid pressure supply valve 33 arranged to control flow of fluid under pressure from a chamber 39, constantly supplied with fluid under pressure from the main reservoir pipe 2% through a passage 40 extending through the pipe bracket 32 and connected to said chamber, to a chamber 41 which is open through a passage and pipe 42 to the brake cylinder device 2 for applying the brakes on the locomotive unit. A brake cylinder release valve 43 contained in chamber 45 controls communication between said chamber and an atmospheric port 44 for controlling release of fluid under pressure from the brake cylinder device 2 for effecting a release of brakes. The release valve 43 is loosely mounted between operating shoulders 45 on a stem 46 projecting from an application piston 41. Upon supply of fluid to a chamber 48 at one side of the piston 41 said piston is adapted to move the release slide valve 43 to a position for closing communication between chamber 31 and the exhaust port 41% and for then opening the application valve 38 to supply fluid under pressure to the brake cylinder device 2. As fluid is thus supplied to the brake cylinder device the pressure of such fluid in chamber M acts on an enlargement 490i the piston stem M5 and through a choke 50 in a chamber 5| on the opposite side of piston 47, whereby, when the pressure in the brake cylinder device becomes increased to substantially the same degree as acting in the application chamber 48, the piston 41 will be moved in the direction of said chamber to permit closing of the application valve 38 by a spring 52 for thereby limiting the degree of brake application on the locomotive in accordance with the pressure of fluid provided in the application piston chamber 48. If the pressure of fluid in chamber 48 is reduced the opposing pressure in chambers 5! and AI will operate the application piston ii to move the slide'valve 43 to the position in which it is shown in the drawing for thereby releasing fluid under pressure from chamber M and from the brake cylinder device? to effect a release of brakes. In other words, the degree of pressure of fluid provided in the brake cylinder device 2 and thereby the degree of brake application on the locomotive unit may be varied according to the pressure of fluid provided in the application cylinder 48, as well-known.

The application piston chamber 48 is connected through a passage 53 in the bracket to the controlled emergency'valve device 34 and through said device to a passage 54 leading to the equalizing portion 28 and to the reduction chamber cut-oi? valve device 29;

The equalizing portion of the distributing valve device comprises an equalizing piston 58 at one side of which is a chamber 59 open to the brake pipe I9 through'a passage At the opposite side of piston 58' is a valve chamber BI open through a passage 62- to the pressure chamber 35. A main slide valve 63 contained in the chamber BI is loosely mounted between two spaced shoulders 64 provided on a stem 65 projecting from the piston 4'8 for operation by said piston. Contained in a recess in piston stem 65 and mounted to slide on the main slide valve 63 is an auxiliary slide valve 66.

The reduction chamber cut-off valve device 29 comprises a piston ii'fi and a slide valve 69' com 'nected to said piston for movement thereby to either of two different positions. The slide valve 3'8 is contained in a chamber T0 at one side of piston 58 while at the opposite side is a chamber 'I'I containing a spring [2 for urging said piston and. slide valve 59 to the position in which they are shown in the drawing.

The release valve device 3E} comprises a check valve 13 contained in a chamber i i open to passage 56 and arranged to control communication between said chamber and a chamber I5 which is open through a passage I6 to a pipe 1? leading to the interlock device I1. A'springiS in chamber It acts on the check valve T3 for urging it to a closed position. Foropening the check valve 73 against spring 38 a piston 79 is provided. The

piston it has a stem '80 projecting through'a 'chamber 8I at one side of the piston and a bore in the partition separating said chamber from chamber '15 into the latter chamber wherein its tween chambers 75 and BI when the stem is out 'of contact with the check valve I3. A spring 83 in chamber 15 acts on the stem 30 for'urging the valve 82 to its seated position When the valve 82 is unseated by piston I9 chamber 15 and thereby the connected passage 16 will be open to atmosphere through one or more grooves 81% in the piston stem 8%], chamber and thence through an atmospheric port 85. A sealing ring 86 in chamber BI is provided for sealing engagement by piston I9 when in the position for opening the check valve I3.

At the opposite side of piston I9 is a control chamber 8! open to a passage 88 extending through the bracket 32 and connected to the independent release pipe 22.

The controller emergency valve device 34 is provided to either permit a slow or a fast emergency application of brakes on the locomotive in accordance with presence or absence of fluid under pres sure in the controlled emergency pipe 2 I, but

insofar as the invention is concerned it may be considered merely as a means for connecting passages 53 and 54 in the bracket to each other.

The engineers automatic brake valve device 4 comprises a handle 9! having the usual release and running positions for supplying fluid under pressure to the brake pipe I9 for releasing brakes on the locomotive and cars'of a train. The handle .lI also has the usual service position for reducing the pressure of fluid in the brake pipe I9 at a service rate to effect a service application or" brakes on the locomotive and cars of a train, and the usual lap position for limiting the degree of a service reduction in brake pipe pressure in the usual manner. The brake valve handle 9'! also has the usual emergency position for effecting an emergency reduction in pressure in the brake pipe I9 and thereby an emergency application of brakes on the locomotive and cars of a train.

In the running position of the brake valve handle 9! a cavity 92 in the usual rotary valve 93 controlled by said handle opens a passage 94 from the independent brake valve device to an atmospheric passage 95, this communication being closed in all other positions of said handle. In emergency position of the handle SI a maintaining port 96 in the rotary valve (Fig. 4) opens passage M to a chamber 91 containing the rotary valve 93 which chamber is constantly supplied with fluidunder pressure, as well known.

The independent brake valve device 5 comprises a rotary'valve es and a handle I00 for turning said rotary valve to its different positions including a running position in which it is shown in Fig. 1, a release position as shown in Fig. 2 and an application position as shown in Fig. 3. In the running position of the brake valve handle Hit, a cavity I0! in rotary valve 99 connects passage 94 to a passage I82 connected to the independent application pipe 23, while the independent release pipe 22 is vented by way of a passage I 01, a cavity H33 in said rotary valve and an exhaust port Hi4. In the release position of rotary valve 99 a cavity I05 therein connects the independent application passage I232 to the exhaust port I04 while a port, H36 in said rotary valve opens passage I01 to a chamber I08 above the rotary valve and which chamber is constantly supplied with fluid under pressure, as well known. In the application position of the rotary valve 99 (Fig. 3) a cavity I09 therein opens the independent release passage Iill to the exhaust port I04 while a port IIO connects the rotary valve chamber I06 to the independent application passage I02.

The independent application pipe 23, which extends through the locomotive, is adapted to be connected to pipe I! leading to the distributing valve device I through the interlock device H, in a manner which will be later described, except upon an emergency reduction in pressure in the brake pipe 2 when such connection will be closed.

Except for the interlock between the independent application pipe 23 extending through the locomotive and pipe 'Il connected to the distributing valve device just mentioned, the structure so far described is the same as in the instruction pamphlet above referred to and its operation briefly as follows.

Assuming that handle 9| of the automatic brake valve device 4 is in its running position, in which it is shown in the drawing, the brake pipe I 9 will be charged with fluid under pressure and passage 94 from the independent brake valve device will be open to atmosphere through the atmospheric passage 95. Further assume that handle I013 of the independent brake valve device is in its running-position in which the independent application pipe 23 will be connected to passage 94 by way of passage I02 and cavity I0l in the independent brake valve rotary valve 99 and that the independent release pipe 22 is open to atmosphere by way of cavity I03 in said rotary valve and exhaust port I04.

With the brake pipe I9 charged with fluid under prressure the equalizing piston chamber 59 in the distributing valve device will likewise be charged and the parts of the equalizing portion 28 of the distributing valve device will be in their brake release position in which they are shown in the drawing and in which a feed passage III around the piston 58 will be open to permit fluid under pressure to flow from chamber 59 to valve chamber BI and thence to pressure chamber to permit charging of the latter two chambers with fluid at the pressurein the brake pipe. With the main equalizing slide valve 63 in its release position, chambers 'II and 10 at opposite sides of piston 68 in the reduction chamber cut-off valve device 29 are connected to each other through passages H2 and H3 respectively, and a passage H4 in said slide valve whereby spring I2 is permitted to hold the piston 68 and slide valve 69 in their normal position in which they are shown in the drawing. With the slide valve 59 thus positioned a cavity II Ia therein opens passage 5 to passage 16, and passage 54 being connected through the controlled emergency valve device 34 to the application piston chamber 48, said chamber is thereby open to passage I6 and thereby through pipe 1! and the independent release pipe 23 to atmosphere via the independent and automatic brake valve devices, whereby the application portion 21 of the distributing valve device will be permitted to assume its release position for releasing brakes on the locomotive. Passage H4 in the equalizing slide valve 63 is open to a cavity H5 in said slide valve to which the application chamber 36 is also open, by way of a passage II 6, and said cavity is open to the vented passage 54 whereby chambers H and. I in the reduction chamber cut-off valve device 23 and the application chamber 35 are both vented to atmosphere. The reduction reservoir 33 is also vented to atmosphere with the equalizing slide valve 63 in its release position by way of a passage (H, a cavity H3 in said slide valve and an atmospheric Port I I9.

Now let it be assumed that the engineer moves the automatic brake valve device handle 9| from running position to service position for efiectin'g aservice reduction in pressure in brake pipe l9 and that after a desired reduction is thus obtained said handle is moved back to lap position for terminating and limiting such reduction. Upon thus reducing the pressure of fluid in the brake pipe is a corresponding reduction in pressure will occur in equalizing piston chamber 59 in response to which the equalizing piston 58 will move the slide valves 66 and 63 to their service position in which these parts are shown in Fig. 5 of the drawing. In service position of the auxiliary slide valve 66 a service port l22 in the main slide valve 63 is open to valve chamber 6| while at the seat of said main slide valve said port is brought into registry with a passage I23, as a consequence of which, fluid under pressure from the pressure chamber 35 is permitted to flow to the reduction chamber cut-off valve device 29 and through a cavity I24 therein in slide valve 69 to passage Ill leading to the reduction reservoir 33. In service position of slide valve 63 passage H7 is also connected through cavity H8 in said slide valve to passage H3 whereby fluid will be supplied to chamber 13 in the reduction chamber cut-off valve device at the same time as it flows to the reduction chamber 33. When a certain pressure of fluid is thus obtained in chamber Til such pressure acting on piston 58 will move it against spring 72 since chamber H is still vented to atmosphere by way of passage H2, a passage 124 in the main slide valve 63 and the atmospheric port H9, and this movement of said piston and thereby of the slide valve 59 will close communication between passages I23 and H! to terminate flow of fluid under pressure to the reduction chamber 33 and open communication between said passage I23 and passage 54. After this chosen reduction in pressure in pressure chamber 35 by flow into the reduction chamber 33 fluid under pressure from said pressure chamher will flow to passage 54 and thence through the controlled emergency valve device 34 tothe application piston chamber 48 in the application portion of the distributing valve device and actuate said application portion to supply fluid at a corresponding pressure to the brake cylinder device 2 for applying the brakes on the locomotive.

When by flow of fluid under pressure from the pressure chamber 35 and valve chamber 5i to the application piston chamber 48 the pressure of such fluid becomes reduced to a. degree slightly lower than the reduced brake pipe pressure acting in chamber 59, the equalizing piston 58 will move in the direction of the lower pressure for thereby shifting the auxiliary slide valve 66 relative to the main slide valve :33 for lapping the service port I22 to prevent further flow of fluid under pressure from the pressure chambers-5 to the application piston chamber 48 for thereby limiting the degree of brake application in accor-dance with the reduction in pressure in the brake pipe !9 effected by operation of the engineers automatic brake valve device 4.

It is also desired to point out that as fluid under pressure is supplied from th pressure chamber 35 to the application piston chamber 48 for efiecting a service application of brakes, as just described, fluid under pressure from the former chamber will also equalize from passage 54 through cavity H5 in the equalizing slide valve 63 and passage Ht into the application chamber 36.

In case the handle 9| of the engineers automatic brake valve device 4 is moved to emergency position an emergency venting of fluid under pressure from the brake pipe 19 and thereby from equalizing chamber 59 in the distributing valve device will occur. In such a case the equalizing piston 58 will move to an emergency position in which a port I21 in the main slide valve 63 moves into registry with passage I23 to permit flow of fluid under pressure from the pressure chamber 35 to the application piston chamber 48 in the same manner as in effecting a service application of brakes but at a more rapid rate, the reduction chamber cut-off valve device 29 functioning during such operation in the same manner as in efiecting a service application of ibrakes.

It is to be noted however, that in emergency position of the equalizing slide valve 63 a part I28 in the main slide 63 laps passage H6 leading to the application chamber 36 so that fluid will not be supplied to said chamber from the pressure chamber 35 in effecting an emergency application of brakes, although in one position of the controlled emergency valve device 34 supply of fluid to the application chamber 36 will occur for delaying the application of locomotive brakes in the handling of a long freight train which however is not pertinent to the invention.

When the reduction chamber cut-oil valve device 29 moves to its left-hand or cut-off position above mentioned in effecting either a service or an emergency application of brakes, av passage I29 controlled by the slide valve 69 is opened to the valve chamber 70 and also past the left hand end of the main equalizing slide valve 63 to the equalizing valve chamber 5!, whereby chamber 70 will be maintained charged with fluid at the pressure in the pressure chamber 35 to insure that the parts of the reduction chamber cut-oii valve device will remain in their lefthand position as long as the brakes on the locomotive remain applied.

In effecting a service application of brakes a cavity 1 30 in the auxiliary slide valve 56 is adapted to connect passage I 14 in the main slide valve, which is connected to passage 54 and thereby the application piston chamber 48, to a passage [3| which registers with a passage l32-leading to the safety valve device 3| which is thereby operative during the time the application of brakes is being eifected to insure that the pressure in the application piston chamber 48 will not increase above a chosen degree, this communication being closed by the auxiliary slide valve 56 in its lap position for preventing leakage of fluid under pressure through the safety valve device from undesirably reducing the pressure of fluid in the application piston chamber 48. The safety valve device 3| is also connected to the application piston chamber 48 in emergency position of the equalizing portion of the distributing valve device by way of passage, I32 and passage I21'in the main slide valve 63, this communication being maintained as long as the emergency application of brakes is in efiect. Permissible leakage of the safety valve devicej3l is of no consequence when an emergency application of brakes is in efiect since in emergency position of the brake valve handle the maintaining port 96 (Fig. 4) in the rotary valve 93 permits flow of fluid under pressure to the application passage 94 and thence through cavity I! in the independent brake valve device to the independent application pipe 23 which heretofore has been connected directly byway of pipe H to chamber '15 in the release valve device 30 of the distributing valve device, whereby fiuid supplied to the latter chamber will flow past the check valve 13 to passage 54 and thence to the application piston chamber 48 for maintaining the pressure therein at the adjustment of the safety valve device 3!. It is to be noted that this supply of fluid through the maintaining port 96 in the automatic brake valve device to the independent application pipe 23 had to be adjusted, heretofore, to the number of units in the .locomotive and hence the number of application piston chambers 48 in which it was desired that the pressure of fluid be maintained and hence has heretofore been a compromise. According to one feature of the invention the need for the maintaining port 95 has been dispensed with in connection with a brake equipment of the type under consideration but said port willzbe maintained in the brake equipments foruse with a locomotive not employing dynamic brakes.

. When the brakes on the locomotive are applied either in response to a service reduction or an emergency reduction in pressure in the brake pipe the engineer may return the handle 91 of the automatic brake valve device to its release position for recharging the brake pipe l9 and reestabl'ishing communication between passage 94 in the brake valve device and the vent port 95 therein by way of cavity 92 in the rotary valve 93.

Upon such recharge of the brake pipe and thereby of piston chamber 59 of the distributing valve device the parts of the equalizing portion will be returned to their release position in which the pressure chamber 35 will be recharged with fluid under pressure and valve chamber 10 in the reduction chamber cut-off valve device 29 will be opened by way of passage 29 and passage I [4 in the main slide valve to passage I 12 leading to piston chamber H whereupon the pressures of fluid in' chambers 10 and H will be equalized to permit spring 52 to return piston 68 and the slide valve 69 to their normal position. When the slide valve 69 thus obtains normal position the application piston chamber 43 and application chamber 36 will be vented to atmosphere by way of passage 54 cavity U la in the reduction chamber cut-off valve device 29, thence through passage 16, pipe H, the independent application pipe 23 and the brake valve devices 3 and 4, whereby the locomotive brakes will be released.

Now let it be assumed that with the brakes on the locomotive applied with the engineers automatic brake valve device 4 either in service lap position or in emergency position the engineer desires to release the brakes on the locomotive independently of the brake pipe I9 and hence without effect on the brakes on the cars of a train. To' accomplish this he will move handle I06 of the independent brake valve device from its running position (Fig. 1) to its release position (Fig. 2). In release position of the independent brake valve device fluid under pressure will be supplied to the independent release pipe 22 and thence to piston chamber 8'! in the release valve device 30. The pressure of fluid thus provided in chamber 81 will operate the independent release piston 19 to unseat the check valves 82 and 13 to permit flow of fluid under pressure from the application piston chamber 48 to chamber and thence past the open valve 82 and through groove 84 to chamber BI and from the latter chamber to atmosphere through the passage 35. If less than a complete release of brakes on the locomotive is desired then as soon as a desired degree of such release is obtained the engineer may return the independent brake valve device to running position for venting the quick release piston chamber 87 by way of the independent release pipe 22 whereupon the check valve '13 will close to hold the remaining fluid under pressure in the application piston chamber $8 to thereby retain a correspondin degree of brake application on the locomotive. A complete release of locomotive brakes may be obtained by holding the independent brake valve handle I00 in its release position for a sufficient length of time.

It is to be noted that when either an automatic service or an emergency application of brakes on the locomotive is effected fluid supplied by the application portion 21 of the distributing valve device to passage 42 for now to the brake cylinder device 2 to actuate same will also flow past a check valve I33 and then through a choke I34 to passage 16 and through pipe TI to the independent application pipe 23, whereby said pipe and passage will become charged with fluid at the same pressure as acting in the brake cylinder device 2 and thus the same as that acting in the application piston chamber 48 while the brakes on the locomotive are applied. The purpose of this is to have the independent application pipe 23 charged with fluidat the same pressure as. in the application piston chamber 48 when the locomotive brakes are applied so that when said piston chamber is connected to said pipe for eifecting a release of brakes, and particularly a graduated release of brakes by operation of either the automatic brake valve device 4 or independent. brake valve devic 5, there will be no undesired drop of pressure in said piston chamber to charge said pipe which would result in a considerable and uncontrolled reduction and consequent corresponding release of brakes on the locomotive. This is a very important feature of the No. 8EL locomotive brake equipment and according to the nvention is not dispensed with.

At any time, either with the brake pipe [9 fully charged and the brakes on the locomotive and connected cars of a train completely released or after a release of brakes on the loco-motive effected by operation of the independent brake valve device while retaining the brakes on the cars of a train applied, the engineermayreapply the brakes on the locomotive by moving the independent brake valve handle to its application position (Fig. 3) for thereby supplying fluid under pressure to the independent application pipe 23 from which it will flow to pipe Ti and thence through passage 16 and past the independent release check valve 73 to passage 54 and the application piston chamber 48. A release of such application may be obtained by returning the independent brake valve handle me to its independent release'pos'ition (Fig. 2) or if the automatic brake valve device 4 is in its release position the return of the independent brake valve handle 1 rim to its running position will provide'for such release.

The interlock device I! added to the No. 8EL locomotivebrakeequipment in accordance with the invention comprises a .selector valve device 11 I31, an emergency interlock device I38 and a dynamic brake control magnet I239.

The selector valve device I31 comprises a piston I40 at one side of which is a chamber I4I open through a passage I42 to the magnet device I39 and containing a spring I43 acting on the piston for urging it to the position in which it is shown in the drawing. At the opposite side of piston I40 is a chamber I44 open through a passage I45 to the main reservoir pipe 20 and hence adapted to be constantly charged with fluid at main reservoir pressure. A slide valve I46 contained in chamber I44 is connected to a stem I 41 projecting from piston I40 for movement by and with said piston.

The magnet valve device I39 comprises a valve I41 having oppositely arranged seats for controlling communication between a chamber I48 containing said valve and, respectively, a chamber I 49 and an atmospheric exhaust passage I50. The magnet device I39 further comprises a magnet I5I operative upon "energization to actuate valve I'41 to open chamber I48 to passage I50. Upon deenergization "of the magnet 'I5I a spring I52 in chamber I49 is adapted to actuate the valve I41 to open communication between chambers I48 and I49, chamber I49 being open to passage I45 and hence constantly supplied with fluid under pressure from the main reservoir pipe 20. i5I is adapted to be placed in circuit with the locomotive propulsion motor 6 and dynamic braking resistor I when the controller 8 is moved to its dynamic-brake-on position whereby current generated by said motor will act to energize said magnet. When the controller 8 'is in its power-on position the magnet I5I is adapted to be *deenergized.

Thus it will be seen that when the magnet I 5I is deenergized. as it will be "at all times except during dynamic braking, fluid under pressure from passage I45 will flow past the valve I41 to piston chamber MI in the selector valve device I31 and equalize with the pressure of fluid in valve chamber I44 to permit spring 143 to move the piston I40 and the slide valve I46 to their normal position in which they are shown in the may be defined by engagement between said piston and a gasket I55.

According to the invention we may also add a pipe I56 to the locomotive brake equipment on the lead unit only, one end of which pipe is connected to passage 94 extending between the rotary valves 93 and '99 of the automatic and independent brake valve devices 4 and 5, and the other end of the said pipe is connected to a passage I51 -terminating at the seat of the respective selector "slide valve I46. We also add an initial release reservoir I58 which is connected by a pipe and passage I59 to the seat of "the selector slide valve I46. We further connect the pressure chamber 95 in the distributing valve device to the seat of the selector slide valve I46 by way of a pipe and passage I60. The brake pipe I9 is also connected to the seat of slide valve I46 by way of 'a passage I-6I containing a check valve I62 which is arranged to prevent flow -01 fluid under pressure in the direction away from By wires I53 and I54 the magnet 12 said brake pipe but to permit flow in the opposite direction to said brake pipe.

When the power controller 8 is out of dynamicbrake-on position and the magnet I5I is thereby deenergized and the parts of the selector valve device I31, including slide valve I69, are in the position in which they are shown in the drawing the passages I6I, I60 and I51 are all lapped by said valve, while passage I59 and thereby the initial release reservoir I58 are open to atmosphere through a cavity I63 in said slide valve and an atmospheric port I64.

When the dynamic brake controller 8 is moved to its dynamic-brake-on position energizing magnet I5I, the selector piston I40 and slide valve I46 will move to their right-hand position for connecting the added pipe I56 to the atmospheric port I64 by way of cavity I63 and for at the same time connecting the pressure chamber passage I60 through cavity 65 in said slide valve to passage I59 leading to the initial release reservoir I58 and also to passage I-6 I leading to the under side of the check valve I62. The connecting of pipe I56 to atmosphere under this condition is without effect while the connecting or pressure chamber 35 to the initial release reservoir I58 merely permits the pressureof fluidin said chamber to equalize into said reservoir at a pressure lower than in the brake pipe I9 which latter pressure maintains the check valve I62 seated to prevent flow of fluid from the brake pipe to said reservoir. With the pneumatic brakes on the locomotive released this reduction in pressure in the pressure chamber 35-into the-reservoir I58 is without effect.

However, let it be assumed that by operation of the engineers automatic brake valve device 4, the pressure of fluid in the brake pipe I9 has been reduced and the distributing valve device A has operated' to apply the brakes on the locomotive. Under this condition the pressure of fluid in the pressure chamber 35 will be the same as the reduced pressure of fluid in the brake pipe I9,-as will be apparent, thus when the dynamic brakes on the locomotive become efiective and the selector valve moves to its right-hand position in which the pressure chamber 35 is connected to the intitial release reservoir i50 the pressure'of fluid in said pressure chamber'will be promptly reduced into said reservoir to :a degree below that in the brake pipe I9. As a result the equalizing piston 38 and slide valves 63, 66 of the distributing valve device will be pulled back from theirservice or servicelap position to their release position whereupon, by way of the reduction cutofi valve device 29 which will be returned to its normal position upon return of the equalizing portion of the distributing valve device to its release position, the application piston chamber 48 will be placed in communication with pipe .11 and thence connected through the emergency interlock device I38, in a manner which will be later described, to the independent application pipe 23 which will be vented through the independent brake valve device 5., p pe 156, cavity I 63 in the selector slide valve I46 and the exhaust cavity I64 to effect a release of iluid under pressure'from the brake cylinder device 2 and thereby a release of brakes on the locomotive 'independ' ently of the pressure of fluid in the brake pipe and hence independently of the brakes on the cars of the train. It will be noted that with the brake valve handle 9I in either service or service lap position communication between passage 94 and the atmosphere is closed, as hereinbefore described, which would prevent release of fluid under pressure from the independent application pipe 23 by way of the automatic brake valve device, but the added pipe I56, cavity I63 and exhaust port I64 in the selector slide valve I46 accomplishes this result when the dynamic brakes on the locomotive are cut-in at a time the brakes on the cars of a train are applied.

It will thus be seen that even if the fluid pressure brakes on the locomotive are applied at the time the dynamic brakes on the locomotive are cut-in such application of the fluid pressure brakes will be released to avoid both brakes being effective at the same time.

If, while the dynamic brakes on the locomotive are effective, the engineer operates the brake valve device t to effect a further reduction in pressure in the brake pipe I9 and thereby a further application of fluid pressure brakes on the cars of a train, the pressure in the pressure chamber 35 will be correspondingly reduced by flow of fluid under pressure past the check valve I52 in the interlock device I1 to the brake pipe I9 to insure that the equalizing portion of the distributing valve device will remain in its brake release position to maintain the fluid pressure brakes on the locomotive released as long as the dynamic brakes are effective.

Y Also connected to the seat of the selector slide valve I46 are two passages I6? and I68, said slide valve having a port I69 adapted to register with passage I68 in the normal position of said slide valve, and a cavity I10 for establishing communication between said passages in the dynamic braking position of said slide valve. These passages, port and cavity perform no function in the structure shown in Fig. l but are adapted for use with the modification shown in Fig. '1, as will hereinafter be described.

The emergency interlock device I38 comprises a piston I12 at one side of which is a chamber I13 open to atmosphere through a port I14 and at the opposite side is a valve chamber I15 constantly supplied with fluid under pressure from the main reservoir through passage I45. The piston I12 has a stem I16 projecting into chamber I and to which there is connected a slide valve I11 for movement with and by the piston.

I12. Below the piston I12 is another piston I13 of larger diameter than piston I12 and subject on one side to atmospheric pressure in chamber I13 while at the opposite side is a chamber I19 which is open to the brake pipe passage :I6I on the brake pipe side of the check valve I62. When the brake pipe I9 and thereby chamber I19 are charged with fluid under pressure the piston I18 is adapted to move into contact with the piston I12 and actuate the latter and the slide valve I11 to a normal position in which these parts are shown in the drawing. When the brake pipe I9 is vented to effect an emergency application of brakes, a like reduction in pressure will occur in chamber I19 so that the pressure of fluid in valve chamber I15 acting on the piston I12 will move said piston and the piston I18 to a lower emergency position.

In the normal position of the emergency interlock slide valve I11 a cavity I89 therein connects pipe 11 from the distributing valve device I to the independent application pipe 23, this communication being maintained at all times except in case of an emergency application of brakes so as'to permit the distributing valve device to be controlled from the automatic brake valve de:

vice 4 and independent brake valve device 5 m the usual manner.

In emergency position of the emergency interlock slide valve I11, pipe 11 and the independent application pipe 23 are disconnected from eachv other and a maintaining port I8 I in the slide valve I11 registers with the passage connection to pipe 11 whereby fluid under pressure from the main reservoir present in valve chamber I15 is permit-v ted to flow to said pipe and thence past the check valve 13 in the distributing valve device I to the application piston chamber 48 for maintaining the pressur therein and thereby in the brakecylinder device 2 at the adjustment of the safety valve device 3I as long as the brakes remain applied in emergency. It is to be noted that in a,

multiple unit locomotive the pressure in the application piston chamber 48 of each distributing valve device, and thereby the'pressure of fluid in the brake cylinder device connected to such distributing valve device, will be maintained against leakage by the supply of fluid under pressure through the restricted maintaining port I8I on that unit, in contrast to the compromise maintenance heretofore provided through th usual has a cavity I82 for opening pipe I83 to an at-' mospheric passage I84 in the normal position of said slide valve while a port I85 in said slide valve is adapted to permit flow of fluid under pressure from valve chamber I15 to said pipe in the emergency position of said slide valve.

The pipe I83 leads to the dynamic brake cutoff switch device I8 which comprises a, contact I86 arranged to open and close the dynamic brake circuit through the resistor 1. The contact I86 15 carried by one end of the rod I 81 the other end of which is connected to a piston I88. At one side of the piston I88 is a chamber I89 open to pipe I83 and said piston is operative upon supply of fluid under pressure to said pipe and chamber, when the emergency selector device I38 moves to its lower position in effecting an emergency application of brakes, to actuate the contact I86 to its circuit opening position for thereby cutting out the dynamic brakes on the locomotive under such a condition. At all other times, that is,

when the brake pipe is charged with fluid under pressure and durin a service application of brakes'the parts of the emergency interlock device I38 will be in their upper position for ventmg chamber I85 in the cut-out switch device I8. With chamber I89 vented a Spring I90 acting on piston I88 will move the contact I 86 to its circuit closing position to permit operation of the dynamic brakes.

' Description of Fig. 6

In the structure shown in Figs. 1, 1a and above described, when the dynamic brakes on the lo-v comotive are cut into operation and the selector valve device I31 responds thereto, the pressure of fluid in the pressure chamber 35 and the equalizing slide valve chamber M is reduced into the release reservoir I58 to pull. the parts of the equalizin portion of the distributing valve. device back to their release position in case they are in service lap position, and to then maintain said parts in release position by flow of fluid under pressure from the pressure chamber 35 back to the brake pipe past check valve I62 in case of .a further or subsequent reduction in pres sure in the brake pipe I9. Instead of thus permitting air to flow from the pressure chamber 35 back to th brake pipe I9, which would. increase the amount of air which had to be released from the brake pipe by operation of the engineers automatic brake valve device 4 to effect a service application of brakes or a further deree of such application on the cars of a train, the connection of the pressure chamber 35 to the brake pipe by Way of the check valve I62 and to the initial release reservoir I58 may both be dispensed with and the structure shown in Fig... 6 may be employed instead.

According to this modification we add a plug L92 to the dynamic interlock device I! in the passage I61 above the connection between the brake pipe and piston chamber I19 in the emergency interlock device I38 for thereby closing communication between the brake pipe and the selector valve device I31. We further add an equalizing discharge valve mechanism 193 comprising a piston I94 at one side of which is a chamber I95 open to the brake pipe is while at the opposite side is a chamber :95 open to passage I53 in thedynamic interlock device I? and thus vented to atmosphere when the selector valve device I3! is in its normal position and adapted to be connected to passage and pipe I68 and thereby to the pressure chamber 35 when the selector valve device I3? moves to the position assumed when the dynamic brakes on the locomotive are cut into operation. Projecting from the piston I 3 through chamber I96 is a stem I91 on the end of which is a discharge valve I98 arranged to cooperate with a seat for controlling communication between chamber I96 and an atmospheric vent port I99. A spring 200 contained in chamber I36 acts on the piston I94 with a force urging it toward chamber I95.

In operation, when the dynamic brakes on the locomotive are not effective and the parts of the selector valve device I 31 are in their normal position chamber I35 below the equalizing discharge valve piston we will be vented to atmosphere through cavity I63 and vent port 564, while brake pipe pressure acting in chamber 3 95 on piston I94 will hold the parts of the discharge mechanism in the position in which they are shown in the drawing. When the dynamic brakes on. the locomotive are cut into operation with either the fluid pressure brakes on the locomotive released or applied, the pressure chamber 35 and equalizing slide valve chamber BI in the distributing valve device will be opened to chamber I96 below the equalizing discharge valve piston I94. At this time the pressure of fluid in the brake pipe I9 and in pressure-chamber 35 will be substantially the same regardless of whether the dynamic brakes on the locomotive are released or previously applied in response to a reduction in pressure in the brake pipe, as a result of which, the pressures of fluid acting on the opposite sides of the equalizing discharge valve piston I94 will be substantially the same, so that spring 250 will promptly actuate said piston to open the discharge valve IBB for venting fluid under pressure from the pressure chamber 35 and equalizing slide 16 valve. chamber GI. This venting of fluid under pressure from the pressure chamber 35 and equalizing slide valve chamber BI will continue until such pressure is reduced below that in the brake pipe a degree suiiicient for the equalizing piston I94 to move against spring 20H to seat the discharge valve !88. The pressure of spring 290 on the piston I94 is preferably such as to cause the pressure in the pressure chamber 35 and equalizing valve chamber BI to be reduced sufficiently below brake pipe. ressure effective in the equalize ing piston chamber 59 to cause the piston 58 to move to its usual retarded recharge position in sealing contact with a gasket ZGI for thereby limiting flow of fluid under pressure from the brake pipe to valve chamber 6i and pressure chamber 35 to a minimum degree controlled by the usual retarded recharge choke 262, so as to positively insure that the parts of the equalizing portion of the distributing valve device will assume a release position for effecting a release of brakes on the locomotive in case the pneumatic brakes were effective at the time the dynamic brakes were cut into operation or to positively insure that the pneumatic brakes on the locomotive will be prevented from applying so long as the dynamic brakes are in action.

Description Fig. 7

As before described in connection with the structure shown in the Figs. 1, la, when the dy namic brakes on the locomotive are out into operation at a time when the pneumatic brakes are effective the equalizing portion of the distributing valve device returnsto its release position to permit movement of the reduction cut-off valve device 29 to its normal position for connecting the application piston chamber 48 to pipe 71 and.

thence to the independent application pipe 33 through the emergency interlock portion I38 of the dynamic interlock device I? whereby the fluid under pressure in said chamber will be released to atmosphere through said independent applica-' tion pipe, the pipe I56 and the exhaust port I64 in the selector valve device I31. Where the loco motive comprises more than one unit it will be noted that this release of fluid under pressure from the application piston chamber 48 on all units must occur through the independent application pipe 23 and the newly added pipe I56 and in case of a maximum number of units in the locomotive such release of brakes on all units may be undesirably delayed. This may be avoided however by the structure shown in Fig. 7 of the drawing which will insure a positive and quick release of brakes on each unit whenever the dynamic brakes are cut into operation.

According to this modification the connection between the independent release pipe 22 and the distributing valve device I is controlled by a relay valve device 235. The relay valve device 295 comprises a valve 2% contained in a chamber 26'! which is open by way of a passage 208 to the independent release pipe passage 3-8 (Fig. 1) in the distributing valve device. The valve 206 is carried by one end of a stem 209 extending through a chamber ZIO and having its opposite and connected to a plunger 2 I I slidably mounted in a bore in the casing. The chamber H0 is open to the main reservoir pipe 20 and hence adapted to be constantly supplied with fluid under pressure from the main reservoir. A passage 2I2 extends axially through the valve 2%, stem 209'and plunger 2II with one end open to chamber 291 While theopposite end opens through a valve seat provided on plunger 2 to a chamber 213 containing a valve 214 arranged to cooperate with said seat for closing communication between chamber 213 and the passage 2l2. The chamber 2l3 is open to the independent release pipe 22. The valve 2M is connected to one end of a stem 2l5 which slidably extends through a bore in a partition separating chamber 213 from a chamber 2l6 which latter chamber is open to atmosphere through a vent port 2 l i. In chamber 2 It the end of stem 2l'5 is provided with a follower 2l8 engaging one side of a flexible diaphragm 2 I 9 at the opposite side of which is a chamber 229 connected to passage l6! in the interlock valve device l'l via a pipe 22! having a restricted vent 222 to atmosphere. A spring 223 contained in chamber 2| 6 acts on the diaphragm follower M8 for urging said follower and the diaphragm 2l9 to the position in which they are shown in the drawing when chamber 220 is vented. In this position of the diaphragm 2I9 the valve 2M will be unseated from plunger 2| 1 and a spring 224 in chamber 207 will seat the valve 206. The parts of the relay valve device 265 will occupy the position just described, establishing communication between the independent release pipe 22 and the distributing valve device I through pipe 208, as long as the dynamic brakes on the locomotive are not in operation in order to permit usual control by the independent brake valve device of the release valve device 33 associated with the distributing valve device i. According to this modification assage I58 in the interlock valve device I3? is connected to a reservoir 226 which, with the dynamic brakes on the locomotive not operating, will be charged with fluid under pressure from valve chamber M4 in the selector valve device I37 by way of port 169 in the slide valve I46.

When the dynamic brakes on the locomotive are cut into operation at a time when the pneumatic brakes on the locomotive are applied and the selector slide valve I45 moves to its right hand position, the cavity I12 inthe selector slide valve I46 will establish communication between passages I6! and 163 and thereby open the reservoir 226 to pipe 2Z| leading to diaphragm chamber 220 in the relay valve device 235. Fluid under pressure from the reservoir 226 will therefore flow into the diaphragm chamber 220 and deflect the diaphragm 2E9 against the spring 223 for closing valve 2M to. disconnect the distributing valve device I from the independent release pipe 22 and for opening valve 266. Upon opening valve 266 fluid under pressure from the main reservoir pipe 2|] present in valve chamber 291 will flow to pipe 208 and thence through passage 88 in the distributing valve device 39 of the distributing valve device.

piston chamber 8'! will actuate piston F9 to open valve 82 and then open the valve 13 whereupon fluid under pressure from the application piston chamber 48 will be locally vented to atmosphere past these valves and through the groove 84 in j sure from valve chamber I15 through the mainstem 85 to chamber BI and thence to atmosphere 1 through the vent port 85 to thereby provide a quick local release of fluid under pressure from r the application piston chamber and a corresponding quick release of fluid under pressure from the brake cylinder device 2 on the locomotive unit, whereby the pneumatic brakes on the locomotive unit will be promptly released when the dynamic brakes are cut into operation.

18 As fluid under pressure is supplied from the reservoir 226 to diaphragm chamber 229 in the relay valve device 205 to effect operation thereof such fluid will be gradually dissipated to atmosphere through the restricted passage 222 and when the pressure of such fluid is sufliciently reduced the spring 223 will return the diaphragm 2i!) and valve 2M to their normal position, in which they are shown in the drawing, and in which the valve 285 will be closed and the other valve 2 l4 open thereby cutting off supply of fluid under. pressure from the main reservoir to the release piston chamber 8'! in the distributing valve device and venting said chamber to the independent release pipe 22 and thence to atmosphere through the independent brake valve device 5. The volume of reservoir 225 and the flow capacity of the vent port 222 are so related as to insure that the check valve 13 in the release valve device 30 of the distributing valve device will remain open only for a sufficient length of time to obtain the desired release of brakes on the locomotive unit and then promptly close so that in case of an emergency application of brakes occurring immediately following such operation of the quick release device 39 the check valve l3 will be closed to prevent loss of such application on the locomotive unit.

Description Fig. 8

If, while the dynamic brakes on the locomotive are in efiect and the pressure of fluid in the brake pipe is has been reduced to effect the service application of brakes on cars of a train and the pressure in the pressure chamber 35 0f the distributing valve device has been correspondingly reduced, an emergency reduction in pressure in the brake pipe i9 is effected to cause an emergency application of brakes on the locomotive and'carsof a train, the dynamic brakes will be cut-out as previously mentioned, but due to the reduced pressure in the pressure chamber 35 emergency pressurewill not be obtained in the application piston chamber 48 of the distributing valve device and hence the brakes on the locomotive will not be applied to the emergency degree -comotive as quickly as possible and this may be accomplished by the structure as shown in Fig. 8.

According to this modification, a volume reservoir 221 may be added to the emergency interlock device I38 and be charged with fluid under prest-aining choke It! in the normal position of the slide valve I71, whereupon, when said slide valve is moved to its emergency position upon an emergency reduction in pressure in the brake ipe the pressure of fluid in said reservoir will quickly equalize through a cavity 228 in said slide valve into pipe 11 and thence through the distributing valve device into the application.

piston chamber 48 to provide a prompt increase in pressure in said piston chamber to an emergency degree to therebyobtain the emergency The application of brakes on the locomotive. size of the reservoir 22'! -rnay be adequate to thus provide emergency pressure in the application 1 piston chamber t8 even if the emergency reduction of pressure in the brake ipe I9 occurs following a full service reduction in pressure in the brake pipe, in which case, if an emergency reduction in brake pipe pressure occurred with the 19 brake pipe fully charged or following a less degree of service reduction there would be a tendency for the pressure in the application piston chain ber 48 to increase above the emergency degree. This however is prevented since the safety valve device 3| is connected to the application piston chamber 48 in emergency and will limit the pressure obtained therein to the desired emergency degree. After the brakes on the locomotive have been applied by fluid under pressure from the reservoir 22! the application will be maintained at the setting of the safety valve device 3! by the supply of fluid under pressure through the maintaining port It! as previously described.

Summary From the above description it will now be seen that we have provided means adapted to be associated with the No. 8 EL locomotive brake equipment which will prevent an automatic application of locomotive brakes or effect a release of such an application, if effective, when the dynamic brakes on the locomotive are in operation and which will permit usual independent control of the locomotive brakes by operation of the independent brake valve device 5 when the dynamic brakes are in operation. EXcept for the addition of pipe I56 connected to the independent brake valve device 5 and of pipe IE?! connected to pressure chamber 35 no modification of the No. 8 EL brake equipment is necessary for use with dynamic brakes on the locomotive and no feature of said brake equipment is lost by the association of the invention therewith.

Having now described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. In a locomotive brake equipment, in combination, a brake pipe, valv means controlled by opposing pressures of fluid in said brake pipe and a chamber and operative upon a reduction in pressure in said brake pipe below that in said chamber to a brake application position for effecting an application of brakes and operative upon a preponderance in brake pipe pressure over that in said chamber to a brake release position for efiecting a release of brakes, electric braking means operative upon energization to brake the locomotive, and means responsive to energization of said electric braking means to release fluid under pressure from said chamber.

2. In a locomotive brake equipment, in combination, a brake pipe, valve means controlled by opposing pressures of fluid in said brake pipe and a chamber and operative upon a reduction in pressure in said brake pipe below that in said chamber to a brake application position for effecting an application of brakes and operative upon a preponderance in brake pipe pressure over that in said chamber to a brake release position for effecting a release of brakes, electric braking means operative upon energization to brake the locomotive, means responsive to energization of said electric braking means to reduce the pressure of fluid in said pressure chamber, and means for limiting the reduction thus effected in said pressure chamber to a pressure at least as low as that in said brake pipe.

3. In a locomotive brake equipment, in combination, a brake pipe, valve means controlled by opposing pressures of fluid in said brake pipe and a chamber and operative upon a reduction in pressure in said brake pipe below that in said chamber to a brake application position for effecting an application of brakes and operative upon a preponderance in brake pipe pressure over that in said chamber to a brake release position forefiecting a release of brakes, electric braking means operative upon energization to brake the locomotive, and means responsive to energization of said electric braking means to establish acne-way flow communication from said chamber to said brak pipe.

4. In a locomotive brake equipment, in combination, a brake pipe, valve means controlled by opposing pressures of fluid in said brake pipe and a chamber and operative upon a reduction in pressure in said brake pipe below that in said chamber to a brake application position for effecting an application of brakes and operative upon a preponderance in brake pipe pressure over that in said chamber to a brake release position for effecting a release of brakes, electric braking means operative upon energization to brake the locomotive, a reservoir, and means responsiveto deenergization of said electric braking means to vent said reservoir and to energization of said electric braking means to close the vent to said reservoir and open said pressure chambertosaid reservoir.

5. In a locomotive brake equipment, in com bination, a brake pipe, valve means controlled by opposing pressures of fluid in said brake pipe, and a chamber and. operative upon a reductionin pressure in said brake pipe below that in saidchamber to a brake application position for effecting an application of brakes and operative upon a preponderance in brake pipe pressure over that in said chamberto a brake release po-' sition for eiiecting a release of brakes, electric chamber to said brake pipe and responsive to de-,

energization of said electric braking means to disconnect said reservoir from said chamber and vent said reservoir and to also close said communication, and means for preventing flow of fluid under pressure through said communication in the direction from said brake pipe to said chamber but for permitting flow or fluid under pressure in the opposite direction.

6. In a locomotive brake equipment, in combination, a brake pipe, valve means controlled by opposing pressure of fluid in said brake pipe and a chamber and operative upon a reduction in pressure in, said brake pipe below that in said chamber to a brake application position for effecting an application of brakes and operative upon a preponderance in brake pipe pressure over that in' said chamber to a brake release position for efiecting a release of brakes, electric braking means operative upon energization to brake the locomotive, a discharge valve, a movable abutment subject on one side to pressure in said brake pipe and on the opposite side to an oppos ing pressure including pressure of fluid in a sec- 0nd chamber and operative in response to a preponderance of said opposing pressure to open said discharge valve for venting fluid under pressure from said second chamber and in response to a preponderance of brake pipe pressure to close said discharge valve, and means responsive to energization of said electric braking means to open the first named chamber to said second chamber and responsive to deenergization of said electric braking means to close communication between said chambers.

7. In a locomotive brake equipment, in com- 21 bination, a brake pipe, valve means controlled by opposing pressures of fluid in said brake pipe and a chamber and operative upon a reduction in brake pipe pressure below that in said-chamber to a brake application position for effecting an application of brakes and operative upon a certain preponderance in brake pipe pressure over that in said chamber to a position for supplying fluid under pressure from said brake pipe to said chamber at a chosen rate and operativeupon a greater preponderance in brake pipe pressure over that in said chamber to another position for supplying fluid under pressure from said brake pipe .to said chamber at a rate slower than-said chosen rate and operative in both of the two last named positions to effect a release of brakes, electric braking means operative upon energization to brake the locomotive, and means operative upon energization of said electric brake means to establish said greater preponderance of brake pipe pressure over the pressure of fluid in said chamber.

8. In a locomotive brake equipment, in combination, a brake pipe, valve means controlled by opposing pressures of fluid in said brake pipe and a chamber and operative upon a reduction in brake pipe pressure below that in said chamber to a brake application position for effecting an application of brakes and operative upon a certain preponderance in brake pipe pressure over that in said chamber to a position for supplying fluid under pressure from said brake pipe to said chamber at a chosen rate and operative upon a greater preponderance in brake pipe pressure over that in said chamber to another position for supplying fluid under pressure from said brake pipe to said chamberat a rateslower than said chosen rate and operative in both of the two last named positions to effect a release of brakes, equalizing discharge valve means including means arranged to respond to a reduction in pressure in said brake pipe to open said discharge valve for venting fluid under pressure from said chamber and for closing said discharge valve upon establishing said preponderance in brake pipe pressure over that in said chamber, electric braking means operative upon energization to brake the locomotive, and means responsive to energization of said electric braking means to render said equalizing discharge valve means efiective to reduce pressure of fluid in said chamber and responsive to deenergization to prevent operation of said equalizing discharge valve means to reduce pressure of fluid in said chamber.

9. In a locomotivelorake equipment, in combination, a brake pipe, an independent application pipe, an engineers automatic brake valve device having one position for charging said brake pipe, a second position for reducing pressure of fluid in said brake pipe and also having a lap position and comprising a passageway and means for opening said passageway to atmosphere in said one position and for closing communication between said passageway and. atmosphere in said second and lap positions, an engineers independent brake valve device for opening and closing communication between said independent application pipe and said passageway, brake applying meansoperable by fluid under pressure to apply the locomotive brakes, electric means operative upon energization to brake the locomotive, apipe connected at one end to said passageway, and means responsive toenergizationof said electric'means to vent the other end of said. pipeand to. open saidlbrak:

applying means :to said independent application pipe.

10. In a locomotive brake'equipment, in combination, abrak pipe, an independent application pipe, application means operative by fluid under pressure to effect an application of brakes and uponrelease of fluid under pressure a release of brakes, equalizing: means operative by a preponderance inpressure of fluid 'in'a chamber over that 'inpsaid'brake pipe to supply fluid under pressure tosaid application means and operative'by a preponderance in brake pipe pressure over that in said chamber to establisha communication from said application means to said'independent application pipe, an ,engineers automatic brake valve device having a brake: release position for supplying :fiuidunder "pressure to said brake pipe and for opening said independent application pipe to atmosphere and having a service position for venting fluid under pressure from said brake pipe andalso 'havinga lap position and being operative in both said service and lap position to close communication between said independent application pipe and atmosphere, electric braking means operative upon energization to brake said locomotive; and means responsive to energization of said electric braking means to release fluid under pressure from said chamber and also to open said independent application pipe to atmosphere and responsive to deenergization of said electric braking means to terminate such release of fluid under pressure from said chamber and also to close the connection between said independent applicationpipe and atmosphere.

1 In a locomotive brake equipment, in combination, a brake pipe, an independent application pipe, applicationmeans operative by fluid under pressureto effect an application of brakes and upon release of fluid under pressure a release of brakes, equalizing means operative by a preponderance in pressure of fluid in a chamber over that in said brake pipe to supply fluid under pressure to said application means'and operative by a preponderance in brake pipe pressure over that in said chamber to establish a communication from said application means to-said independent application pipe, an engineers automatic brake valve device having a brake release position for supplying fluid under pressure to said brake pipe and for opening said independent application pipe to atmosphere and having a service position for venting fluid under pressure from said brake pipe and also having a lap position and being operative in both said service and lap position to close communication between said independent application pipe and atmosphere, an engineers independent brake valve device controlling communication between said independent application pipe and said automatic brake valv device and having a brake release position for opening such communication and a brake application position for closing such communication, a pipe connected to the said communication between said independent and automatic brake valve devices,

electric braking means operative upon energization to brake said locomotive, and means responsive to energization of said electric braking means to open a communication for releasing fluid under pressure from said chamber, toestablish said preponderance in brake pipe pressure over that in said chamber and also open the last named pipe tosatmosphere and responsive to deenergization ofwsaid electric braking means to close the-last :name'd communication and also to close com- 23 munication between the last named pipe and atmosphere.

12. In a locomotive brake equipment, in combination, a brake pipe, an independent application pipe, brake cylinder means operative by fluid under pressure to efiect an application of brakes and upon release of fluid under pressure to effect a release of brakes, a distributing valve device comprising an application portion operative upon supply and release of fluid under pressure, respectively, to correspondingly vary pressure of fiuid'in said brake cylinder means, and an equalizing portion operative upon a reduction in pressure in said brake pipe below that in a chamber to supply fluid under pressure to said application portion and operative upon a preponderance in brake pipe pressure over that in said chamber to open said application means to said independent application pipe, a restricted communication opening said brake cylinder means to said independent application pipe, an engineers brake valve device having a :brake release position for opening said independent application pipe to atmosphere and having another position for reducing pressure of fluid in said brake pipe and closing communication between said independent application pipe and atmosphere, electric braking means operative upon energization to brake the locomotive, and means responsive to energization of said electric braking means to establish said preponderanc in brake pipe pressure over that in said chamber and to also open a vent from said independent application pipe.

13. In a locomotive brake equipment, in combination, a brake pipe, an independent application pipe, a distributing valve device comprising an application portion operative upon supply and release of fluid under pressure to and from a chamber to, respectively, efiect application and release of locomotive brakes, and an equalizing portion operative upon a reduction in brake pipe pressure to supply fluid under pressure to said chamber and upon an increase in pressure in said brake pipe to open said chamber to said independent application pipe, an engineers brake valve device having one position for supplying fluid under pressure to said brake pipe and for opening said independent application pipe to atmosphere and having service and emergency positions for venting fluid under pressure from said brake pipe and closing communication between said independent application pipe and atmosphere, valve means controlling communication through said independent application pipe between said distributing valve device and brake valve device operative only upon an emergency reduction in brake pipe pressure to close such communication and to open a fluid pressure supply communication to said independent application pipe, and a communication by-passing said equalizing portion providing for flow of fluid under pressure only in the direction from said independent application pipe to said chamber.

14. In a locomotive brake equipment, in combination, a brake pipe, an independent application pipe, a distributing valve device comprising an application portion operative upon supply and release of fluid under pressure to and from a chamber to, respectively, effect application and release of locomotive brakes, and an equalizing portion operative upon a reduction in brake pipe pressure to supply fluid under pressure to said chamber and upon an increase in pressure in said brake pipe to open said chamber to said independent application pipe, an engineers brake 24 valve device having one position for supplying fluid under pressure to said brake pipe and for opening said independent application pipe to atmosphere and having service and emergency positions for venting fluid under pressure from said brake pipe and closing communication between said independent application pipe and atmosphere, a source of fluid under pressure, a volume, means providing a constantly open restricted communication from said source to said volume, valve means operative by fluid from said brake pipe, when in excess of a chosen degree, to open communication through said independent application pipe from said distributing valve de vice to said brake valve device and operative when at a lower degree to close the last named communication and to open said volume to the portion of said independent application pipe connected to said equalizing portion, and a communication by-passing said equalizing portionv providing for flow of fluid under pressure only in the direction from said independent application pipe to said chamber.

15. In a locomotive brake equipment, in-com-' bination, a brake pipe, an independent application pipe, a distributing valve device comprising an application portion operative in response to supply and release of fluid under pressure to a chamber, respectively, to apply and release the locomotive brakes, an equalizing portion operative upon a reduction in brake pipe pressure to supply fluid under pressure from a pressure chamber to said application portion and upon a preponderance in brake pipe pressure over that in said pressure chamber to open said application portion chamber to said independent application pipe, an engineers brake valve device having one position for supplying fluid under pressure to said brake pipe and for opening said independent application pipe to atmosphere and having a service position for effecting a service reduction in brake pipe pressure and an emergency position for eifecting an emergency reduction in pressure in said brake pipe and operative in all positions except said one position to close the connection between said independent application pipe and atmosphere, electric braking means operative upon energization to brake the locomotive, means responsive to energization of said electric braking means to release fluid under pressure from said pressure chamber for establishing said preponderance in brake pipe pressure over that in said pressure chamber and to open said independent application pipe to atmosphere and responsive to deenergization of said electric braking means to close the fluid pressure release communication from said pressure chamher and the connection between said independent application pipe and atmosphere, a switch for effecting deenergization of said electric braking means, means responsive to an emergency reduction in brake pipe pressure to open said switch and establish a fluid pressure supply communication to said independent application pipe, and a one-way flow communication providing for flow of fluid under pressure from said independent application pipe to said application portion.

16. In a locomotive brake equipment, in combination, a brake pipe, an independent application pipe, a safety valve device, a distributing valve device comprising an application portion operative in response to supply and release of fluid under pressure to and from a control chamber to apply and release the locomotive brakes,

apressure chamber, an equalizing portion re-l aevcgoea 25.1 sponsive to a preponderance in. brake pipe pressure over that in said pressure chamber to open said control chamber to said independent appli cation pipeand said-pressure chamber to said brake pipe and responsive toeither a service or an emergency reduction in brake pipe pressure for opening said pressure chamber to said control' chamber and: to" close communication between said control chamber and independent application pipeandalso operative upon an emergency reduction inbrake pipepressure toopen said control chamber tosaid safety valve device, an engineers automatic-brake valvedevice having a brake release positiontor opening said independentapplication pipe to atmosphere 7 and for supplying fluid under pressure to said brake pipe and having service and emergency positions for effecting, respectively,-service andemergency rates of reduction in pressure insaid brake pipe, and a lapiposition for closing. off supply of 'fluid und'er pressure to and releaseof fluid under pressureirom said brake pipe being also operative in the service, emergencyand lap positions to close communicationbe tweensaid independentrelease pipe and atmosphere an engineers A independent brake valve device controlling communication between said independent application pipe and said automatic brake valve deviceand having arr-inning posi tion foropening such communication and an application position for closing such communication and for supplying-fluid und'er pressure to the portion-ofsaid independent application pipe connected to said distributing valve device, an interlock valve: controlling communication through said independentapplication pipe from said distributing valve device to said-independent brakevalve device" and'operative by brake" pipe pressure when in excessof a chosen degree to open such communication and when at a lower degree to close such communication and supply fluid under pressure to the portion of said independent application pipe leading to said dis munication connecting said independent appli-' cation pipe to said control chamber in by-passing relation to said equalizing portion to provide for flow of fluid under pressure only inv the direction to said control chamber.

17.. In a locomotive brake equipment, in com.- bination', a brake pipe, an independent application pipe, a safety valve device, a distributing valve device comprising an application portion operative in response to supply and release of fluid under pressure to and from a control chainber to apply and release the locomotive brakes, a pressure chamber, an equalizing portion responsive to a preponderance in brake pipe presture over that in said pressure chamber to open said control chamber to said independent application pipe and said pressure chamber to brake pipe and responsive to either a service or an emergency reduction in brake pipe pressure for opening said pressure chamber to said control chamber and to close communication between said control chamber and independent application pipe and also operative upon an emergency reduction in brake pipe pressure to open said control chamber to said safety valve device, an engineers automatic brake valve device having a brake release position for opening said independent application pipe to atmosphere and for supplying fluid under pressure to said brake pipe and having service and emergency positions for effecting, respectively, service and emergency rates of: reduction in pressure in 1 saidi brake: pipes" and a lap position for closing on supply of: fluid under pressureto andv release of fluidlunderpres' sure from said brake pipe and being-a1soopera-. tive in the service, emergencyand lap positions: to close communication betweensaid independa ent release pipe and atmosphere, ani engineers independent brake valve device controlling com munication between said independent application pipe and said automatic brake valve device and having a running position-for opening sucl i communication and an application position: for closing such communication. and for supplying fluid under pressure to-the portion of said iride pendent application i pipe connected to said distributing valve device, an interlock valve con-'-- trolling communication through said ind'epend'entapplication pipe from said distributing valve device to said independent brake valve device and-= operative by brake pipe pressure when in -excess: of .a, chosen degree toopen such communication and when at a-lower degree tocl'ose suchcom munication and supply fluid under pressure--to the portion of: said independent application ipe leading to said distributingvalve: device, a oneway-flow communication: connecting said inde pendent application pipe to said-control chamberin by-passing relation to said equalizing-portion to provide for flow of fluid underprcssure only in the direction to said. control chamber, electricbraking means operative: upon energi-zation to brake the locomotive, means responsive to :energization of said electric braking means to reduce the pressure in said pressure chamber below that in said brake pipe for moving said" equalizingpor tion to its releaseposition and for al'so opening to atmosphere the portion of said independentapplication pipe extending between the erigi' neers automatic and independent brake-valve device, and operative upon deenergization'ofsaid electric means to close the vent from said' pres sure chamber and the: respective atmospheric connection of saidindependent application-pipe, and a switch for efiecting deenergization of saidelectric means, said interlock 'valvecomp singmeans operative upon. operation thereof- "re sponse to said lower degree of -brake-pip pres--- sure to. effect operation of: said' -swi't'ch to senergizesaid electric means.

18. In a locomotive brake equipment; com bination, a brake pipe, a distributing valvedevi'ce comprising an application portion ope able-inresponse to supply andrelease of und pressure to apply and release, respectively, locomotive brakes, an equalizing portion operative upon a reduction in pressure in said brake pipe to supply fluid under pressure from a pressure chamber to said application portion and operative upon a preponderance in pressure in said brake pipe over that in said chamber to cut off supply of fluid under pressure to said application portion, and a release portion operable by fluid under pressure to release fluid under pressure from said application portion, electric means operative upon energization to brake the locomotive, and means responsive to energization of said electric means to effect said preponderance in pressure and to supply fluid under pressure to said release portion, and means for limiting the time which said release portion is operated by such fluid pressure.

19. In a locomotive brake equipment, in combination, a brake pipe, a distributing valve device comprising an application portion operable in response to supply and release of fluid under pressure to apply and release, respectively, loco-- motive brakes, an equalizing portion operative upon a reduction in pressure in said brake pipe to supply fluid under pressure from a pressure chamber to said application portion and operative upon a preponderance in pressure in said brake pipe over that in said chamber to cut oif supply of fluid under pressure to said application portion, and a release portion operable by fluid under pressure to release fluid under pressure from said application portion, electric means operative upon energization to brake the 1000- motive, a reservoir, relay means arranged to be operated by fluid under pressure from said reservoir to supply fluid under pressure to operate said release portion, means for gradually releasing the actuating fluid under pressure from said relay means and reservoir, means for operating said relay means to release actuating fluid under pressure from said release portion upon a reduction in pressure of such fluid to a chosen degree, and means operative upon deenergizationof said electric means to charge said reservoir with fluid under pressure and upon energization of said electric means to connect said reservoir to said relay means and to also vent fluid under pressure from said pressure chamber to establish said preponderance in brake pipe pressure.

20. In a locomotive brake equipment, the combination with a brake pipe, an independent application pipe, a distributing valve device comprising an application portion responsive to supply and release of fluid under pressure to apply and release, respectively, brakes on the locomotive, an equalizing portion responsive to a reduction in pressure in said brake pipe below that in a pressure chamber to supply fluid under pressure from said chamber to said application portion and operative by a preponderance in pressure in said brake pipe over that in said pressure chamber to open said application portion to said independent application pipe,'a communication by-passing said equalizing portion connecting said independent application pipe to said application portion, a check valve for closing said communication against flow of fluid under presure in the direction toward said lIldB, pendent application pipe, a releaselpiston operable by fluid under pressure to unseat said check valve, another valve controlling communication between said independent application pipe and' atmosphere and opened by operation of said release piston by fluid under pressure, electric means operative upon energization to brake the: locomotive, and means responsive to energization,

of said electric means to establish said preponderance in brake pipe pressure and to supply fluid under pressure to said release piston to operate same. 7

21. In a locomotive brake equipment, the combination with a brake pipe, an independent application pipe, a distributing valve device comprising an application portion responsive to supply and release of fluid under pressure to apply and release, respectively, brakes on the locomotive, an equalizing portion responsive to a re-' duction in pressure in said brake pipe below that in a pressure chamber to supply fluid under pressure from said chamber to said application portion and operative by a preponderance in pressure in said brake pipe over that in said pressure chamber to open said application portion to said independent application pipe, a communication by-passing said equalizing portion connecting said independent application pipe to said application portion, a check valve for closing said communication against flow of fluid under pressure in the direction toward said independent application pipe, a release piston operablebyfluid under pressure to unseat said check valve, another valve controlling communication be tween said independent application pipe and atmosphere and opened by operation of said rev lease piston by fluid under pressure, an independ: ent release pipe, an engineers independent brake valve device having one position for venting said independent release pipe and another position a for supplying fluid under pressure thereto, electric means operative upon energization .to brake the locomotive, and meansresponsive to energization of said electric means to, establish said preponderance in brake pipe pressure, to close communication between said independent release pipe and said release piston and to supply fluid under pressure to said release piston to operate same and operative upon deenergization to open said release piston to said independent release pipe.

References Cited in the file of this patent UNITED STATES PATENTS Number Name 7 Date 1,439,467 Farmer Dec. 19, 1922. 1,442,305 Steams et al Jan. 16, 1923 2,445,680 Linhart July 20, 1948 p 

